When a chemical reaction is performed in a reactor, fouling phenomenon that a reaction product is adhered to a wall surface of the reactor occurs in some cases. When fouling is generated, it becomes difficult to remove heat from a reactor wall surface, and thus it becomes difficult to control a reaction temperature, and as the most severe situation, a runaway reaction is caused in some cases. And, once fouling has occurred, it is difficult to remove fouling while an operation is continued, and therefore it is necessary to open the reactor and clean it, and a reduction in productivity is caused in some cases.
Fouling becomes a remarkable problem, particularly, in a polymerization reaction. In order to suppress fouling in a polymerization reaction, a method of adding a specific surfactant to a reaction system is known (Patent Document 1, Patent Document 2).
Since many of surfactants have a pour point around room temperature, and exhibit a nature of a paste state or a liquid state in which a part is precipitated in many cases, pipe clogging is caused in some cases, when a surfactant having deteriorated flowability is added to a reactor through the pipe as it is.
And, since the surfactant has a hydrophilic group, it has hygroscopy, and among commercially available surfactants, many of them are sold in the state where water is contained. When water prevents progression of a chemical reaction, it is necessary to remove water in the surfactant before addition to a reaction system. Patent Document 2 describes a dehydration method by nitrogen bubbling, but there is a disadvantage that since the surfactant generally has foamability, the surfactant becomes to have a foamy nature due to bubbling, and addition to the reaction system thereafter becomes difficult.
Further, since solubility of the surfactant sensitively responds to a temperature, it is preferable to provide an apparatus for temperature regulation in a storage tank or a supply line, in order to handle the surfactant in the state of a uniform solution. Patent Document 2 describes a method of adding, to a reactor, the surfactant as a hexane solution, a temperature of which is regulated at 50° C. However, since in a facility not having these apparatuses, a special facility for temperature regulation becomes necessary, this results in disadvantage from a view point of the cost.